API Test Engineer

API Test Engineer - Job Description (JD)

Job Title

API Test Engineer

Job Summary


We are looking for a skilled API Test Engineer to design, develop, and execute API testing strategies to ensure the quality, reliability, performance, and security of RESTful and SOAP web services. The ideal candidate should have experience with API automation, manual API testing, database validation, CI/CD integration, and testing tools such as Postman and REST Assured.


Key Responsibilities

• Design and execute API test cases for REST and SOAP services.
• Develop and maintain API automation frameworks.
• Validate API functionality, performance, reliability, and security.
• Perform request and response validation using JSON and XML.
• Test CRUD operations (GET, POST, PUT, PATCH, DELETE).
• Verify authentication and authorization mechanisms (OAuth 2.0, JWT, API Keys).
• Perform database validation to ensure data integrity.
• Identify, log, and track defects using defect management tools.
• Integrate API automation into CI/CD pipelines.
• Collaborate with developers, QA engineers, and DevOps teams.
• Create API test plans, reports, and documentation.
• Participate in Agile/Scrum ceremonies.

Required Skills

API Testing

• REST API Testing
• SOAP API Testing
• GraphQL API Testing
• Web Services Testing
• JSON & XML Validation
• Protocol
• CRUD Operations
• API Versioning

API Automation Tools

• REST Assured (Java)
• Postman
• Newman
• Karate Framework
• SoapUI
• Insomnia

Programming Languages

• Java (Preferred)
• Python
• JavaScript
• C#

Knowledge of:

• Object-Oriented Programming (OOP)
• Exception Handling
• Collections
• File Handling
• JSON Parsing

API Authentication

• OAuth 2.0
• JWT (JSON Web Token)
• API Key Authentication
• Basic Authentication
• Bearer Token Authentication

API Concepts

• Methods
  
  
  • GET
  • POST
  • PUT
  • PATCH
  • DELETE
• Status Codes
• Request Headers
• Query Parameters
• Path Parameters
• Request Body
• Response Validation
• Cookies
• Sessions

Database Testing


Experience in validating backend data using:

• SQL
• MySQL
• PostgreSQL
• Oracle
• SQL Server

Knowledge of:

• Joins
• Stored Procedures
• Views
• CRUD Operations
• Data Validation

CI/CD & DevOps


Experience with:

• Jenkins
• Git
• GitHub
• GitLab
• Azure DevOps
• Maven
• Gradle
• Docker

Responsibilities:

• Execute API automation in CI/CD pipelines.
• Generate execution reports.
• Schedule automated regression runs.

Performance Testing (Preferred)

• JMeter
• LoadRunner
• API Load Testing
• Stress Testing
• Spike Testing

Security Testing (Preferred)

• OWASP API Security
• SQL Injection Testing
• Authentication Testing
• Authorization Testing
• Rate Limiting Validation
• API Vulnerability Testing

Reporting & Defect Management


Experience with:

• JIRA
• Azure DevOps
• Bugzilla
• ALM/Quality Center

Reporting Tools:

• Allure Reports
• Extent Reports
• Newman Reports

Preferred Qualifications

• Bachelor's degree in Computer Science, Engineering, or a related field.
• 2-6+ years of experience in API testing and automation.
• Hands-on experience with REST Assured or Postman automation.
• Good understanding of SDLC, STLC, and Agile methodologies.
• Experience working with microservices architecture.

Nice to Have Skills

• Selenium WebDriver
• Playwright
• Cypress
• Kafka Testing
• RabbitMQ Testing
• Docker & Kubernetes
• Cloud platforms (AWS, Azure, GCP)
• Contract Testing (Pact)
• Mock Servers (WireMock)

Sample Project Responsibilities

• Develop REST Assured automation for microservices APIs.
• Validate request and response payloads against API contracts.
• Perform end-to-end API testing integrated with UI automation.
• Execute regression API suites in Jenkins.
• Validate backend database updates after API execution.
• Perform API performance testing using JMeter.
• Secure APIs by validating authentication and authorization mechanisms.

Sample API Automation Framework

Framework Components

• REST Assured - API automation
• Java - Programming language
• TestNG/JUnit - Test execution
• Maven - Dependency management
• Jackson/Gson - JSON serialization/deserialization
• Log4j - Logging
• Extent Reports/Allure - Reporting
• Jenkins - CI/CD
• Git - Version control

Execution Flow

1. Jenkins triggers the build.
2. Maven downloads dependencies.
3. TestNG executes API test cases.
4. REST Assured sends requests.
5. Responses are validated against expected results.
6. Database validation is performed (if required).
7. Reports are generated and published.
8. Results are shared with the QA team.

Interview Questions

API Basics

1. What is an API?
2. What is the difference between REST and SOAP?
3. Explain methods (GET, POST, PUT, PATCH, DELETE).
4. What are status codes?
5. What is idempotency in REST APIs?

REST Assured

1. How do you automate APIs using REST Assured?
2. How do you validate JSON responses?
3. How do you extract values from API responses?
4. How do you perform parameterization in REST Assured?

Authentication

1. Explain OAuth 2.0.
2. What is JWT?
3. How do you pass authentication tokens in API requests?

Database Validation

1. How do you validate database changes after an API call?
2. Explain SQL joins used during API testing.

CI/CD

1. How do you integrate API tests into Jenkins?
2. How do you execute Postman collections using Newman?

Scenario-Based

1. How do you test an API when documentation is unavailable?
2. How would you validate an API returning intermittent 500 errors?
3. How do you test pagination and filtering APIs?
4. How do you handle dynamic values such as tokens or session IDs?

Key Skills for Resume

• REST API Testing
• REST Assured
• Postman
• Newman
• SoapUI
• Karate Framework
• Java
• JSON
• XML
• OAuth 2.0
• JWT
• SQL
• MySQL
• Oracle
• PostgreSQL
• Jenkins
• Maven
• Git
• Docker
• JIRA
• TestNG
• JMeter
• API Automation
• Microservices Testing
• CI/CD
• Agile Testing